CANBERRA - Australia is in talks with the United States about a stronger American military presence in its north, the government said on Thursday, amid reports US President Barack Obama will make an announcement during a visit to Australia next month.

Defence Minister Stephen Smith said Canberra, a close US ally with troops in Afghanistan, was in discussions on holding more exercises alongside US forces, and pre-positioning US weapons and stores in Australia's remote tropical north.

Washington and Canberra have been examining a stronger American presence in Australia's north for months.

"We've been working closely to look at the possibility of more training, more exercises, what I colloquially describe as more troops in, troops out, more ships in, ships out and more planes in and planes out," Smith told Australian radio.

Smith said a deal would involve no permanent bases. But news reports in the northern city of Darwin said talks had considered frequent visits by US warships and submarines, with some to be based in Darwin for part of the year.

Darwin, the capital of the outback Northern Territory, promotes itself as a gateway to Asia, lying closer to Indonesia and southeast Asia than to Australia's heavily-populated eastern coastline.  

Smith said there had been discussions about buying land near the Australian military's Robertson Barracks in Darwin to house US personnel and equipment.

Obama will visit the Northern Territory and the capital Canberra on Nov 16-17, after attending an Asia-Pacific summit in Hawaii and ahead of an East Asia leaders' summit on the Indonesian resort island of Bali.

Smith, wary of provoking Australia's biggest export customer, Beijing, said the United States was looking only at pre-positioning stores and equipment mainly for "disaster relief and humanitarian assistance in our region".

"We're not looking at US bases. It'd be more through traffic. We have a number of facilities in the Northern Territory where there is a possibility that greater engagement could occur," he said.

Australia is also looking at moving warships and aircraft to military bases in the north and resource powerhouse state Western Australia to protect oil and gas projects thought to be vulnerable to attack in the event of a regional clash.

Canberra has already begun a multi-billion-dollar upgrade of its military that includes new air defence destroyers, stealth fighter aircraft, two large amphibious assault carriers, helicopters, tanks, long-range cruise missiles and 12 new submarines costing $25 billion.